1. Field of the Invention
The present invention relates to a digital camera onto which a recording medium can be loaded, said medium capable of recording photographed image data and prohibiting the recorded image data from being erased.
2. Description of the Related Art
In recent years, with the increase in resolution of image pickup elements such as CCDs (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) image sensors, the demand for digital cameras has been rapidly increasing.
In such digital cameras, in general, image data obtained through an image pickup element by photographing is recorded on a portable recording medium loaded in the digital camera. In recent years, several types of digital cameras that are configured to accommodate various types of recording media have been manufactured.
Portable recording media that can be used in digital cameras of this type include many types of recording media such as Smart Media (Trademark), SD (Secure Digital) cards, memory sticks, Compact Flash (Trademark), and Microdrives are known. These recording media are provided with the following features in order to prevent recorded information from being erroneously erased.
The SD card and the memory stick have write-protect switches. When the switch is set to write-protect, recorded data is prevented from being erroneously erased. Furthermore, a write-protect seal is stuck on Smart Media, hence recorded data can be prevented from being erroneously erased.
A technology for preventing recorded data on an IC memory card from being erroneously erased is known (see Japanese Patent Application Laid-Open (JP-A) No. 2001-22913) in which a write-protect terminal, which can prevent data from being written by sticking an insulating sheet, is arranged on an IC memory card.
These technologies are used to simultaneously prevent all pieces of data on a recording medium from being erroneously erased. In a digital camera onto which these recording media can be loaded, when the loaded recording medium is set in an erroneous erase protect state, new data is not recorded on the recording medium, and recorded data is not erased as a matter of course. In addition, the digital camera is designed not to initialize (also referred to as “format” in this specification) the recording medium.
In addition to the above-mentioned technology for simultaneously preventing all pieces of data recorded on the recording medium from being erroneously erased, a technology for preventing data recorded as units of files from being erroneously erased is known. That is, a recording medium is designed such that a read-only attribute can be set for each file. The read-only attribute is set for only a file to be prohibited from being erased, so that the data is prevented from being erroneously erased as units of files. In this technology, the recording medium is initialized and all the pieces of information are erased regardless of the settings of the read-only attributes.
However, in some recording media such as Microdrive, simultaneous prevention of all pieces of recorded data from being erroneously erased has not been achieved, and only prevention of erroneous erasing in units of files can be performed by the read-only attributes.
Therefore, if a digital camera is designed such that a recording media of this type can be loaded, when the loaded recording medium is instructed to initialize, all pieces of data are erased, regardless of the settings of read-only attributes.
The present invention has been made to solve the above problems. The present invention provides a digital camera onto which a recording medium, which has image data set to be prohibited from being erased is recorded, is loaded and which can prevent the image data from being inadvertently erased when the recording medium is instructed to initialize. Further, the invention provides a method for preventing erasure in the digital camera.